JF
John Frederick — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Baltimore-City-County, Maryland
Our Model Tree links this John Frederick across the 1920, 1930 and 1940 US Censuses in Baltimore-City-County, Maryland (XGBoost, ~Confirmed) — first a head (b.~1886), then head of a 12-person household.
Age 54
b. ~1886
Male
Head
Born: Maryland
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Baltimore-City-County, Maryland |
| Surname | Frederick |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | Black |
| Age | 54 |
| Marital Status | Married |
| Birthplace | Maryland |
| 1935 Residence (City) | Baltimore |
| 1935 Residence (County) | Baltimore |
| Additional Details | |
| Occupation | Laundryman |
| Industry | Laundry |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 468 |
| Highest Grade | No 4 |
| 1935 Residence | Same place |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
| Occupation | Laundryman |
| Township / Ward | Baltimore |
| Est. Birth Year | ~1886 |
Household Members
Census records only state relationship to the household head.
Pairwise kinship is derived (~90–95% accurate), not recorded.
Step/blended families and boarders can break it.
12 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Henrietta Frederick | Daughter | — | 9 | ~1931 |
| William Ridgley | Other | — | 1 | ~1939 |
| Celeste Berrigan | Other | — | 24 | ~1916 |
| Mary Ridgley | Daughter | — | 21 | ~1919 |
| Bernice Frederick | Daughter | — | 15 | ~1925 |
| Louise Frederick | Daughter | — | 17 | ~1923 |
| Ida Frederick | Spouse | — | 48 | ~1892 |
| John Frederick | Head | — | 54 | ~1886 |
| Thomas Berrigan | Other | — | 33 | ~1907 |
| Ethel Frederick | Daughter | — | 13 | ~1927 |
| Thomas Ridgley | Other | — | 20 | ~1920 |
| Robert Frederick | Son | — | 19 | ~1921 |
Census Appearances
1920
Baltimore, Maryland
Head, age 36
Baltimore, Maryland · implied b. ~1884
●
Primary link
· ~Confirmed · 1 source
XGBoost
| Surname | Frederick |
| Given Name | John G |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 36 |
| Marital Status | Married |
| Birthplace | Maryland |
| Father's Birthplace | Maryland |
| Mother's Birthplace | Maryland |
| Occupation | Painter |
| Industry | Ship Bldg |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Home Owned/Rented | O |
| Home Free/Mortgaged | F |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
1930
Baltimore, Maryland
Head, age 47
Baltimore, Maryland · implied b. ~1883 — 12 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Frederick |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | Black |
| Age | 47 |
| Marital Status | Married |
| Birthplace | Maryland |
| Age at First Marriage | 22 |
| Father's Birthplace | Maryland |
| Mother's Birthplace | Maryland |
| Occupation | Washer |
| Industry | Laundry |
| Class of Worker | W |
| Can Read/Write | Yes |
| Home Owned/Rented | R |
| Home Value / Rent | 5 |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
1940
Baltimore-City-County, Maryland
Head, age 54
Baltimore-City-County, Maryland · implied b. ~1886 — 12 household members
| Surname | Frederick |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | Black |
| Age | 54 |
| Marital Status | Married |
| Birthplace | Maryland |
| 1935 Residence (City) | Baltimore |
| 1935 Residence (County) | Baltimore |
| Occupation | Laundryman |
| Industry | Laundry |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 468 |
| Highest Grade | No 4 |
| 1935 Residence | Same place |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
Model Tree
An inferred pedigree reconstructed from census links — up to 4 generations within the 1900–1950 window. Closer generations are built from household co-residence; deeper ones are bridged by following a relative to their own childhood census. Confidence compounds and weakens with each generation.
Our Model Tree links John Frederick across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Frederick
Head · 1940 · age 54 · b. ~1886 · Maryland
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Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Baltimore-City-County, Maryland
Open full size
1940 US Federal Census — Baltimore-City-County, Maryland
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01523-00277)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Joshua Thomas | 52 | Head | Domestic | Maryland |
| 2 | Alice Thomas | 19 | Daughter | Domestic | Maryland |
| 3 | John Henson | 28 | Son-in-law | Laborer | Maryland |
| 4 | Catherine Henson | 20 | Daughter | — | Maryland |
| 5 | John Jr. Henson | 7 | Grandson | — | Maryland |
| 6 | Bertha Henson | 5 | Granddaughter | — | Maryland |
| 7 | Charles O. Thomas | 4 | Grandson | — | Maryland |
| 8 | Katherine A. Thomas | 1 | Granddaughter | — | Maryland |
| 9 | Sara Ruff | 70 | Mother | — | Maryland |
| 10 | Oliver Ruff | 18 | Brother | New Worker | Maryland |
| 11 | Lafayette Thomas | 4 | Grandchild | — | Maryland |
| 12 | John Frederick THIS PERSON | 54 | Head | Laundryman | Maryland |
| 13 | Ida Frederick | 48 | Wife | Maid | Maryland |
| 14 | Robert Frederick | 19 | Son | New Worker | Maryland |
| 15 | Louise Frederick | 17 | Daughter | — | Maryland |
| 16 | Bernice Frederick | 15 | Daughter | — | Maryland |
| 17 | Ethel Frederick | 13 | Daughter | — | Maryland |
| 18 | Henrietta Frederick | 9 | Daughter | — | Maryland |
| 19 | Thomas Ridgley | 20 | Son-in-law | Machine Worker | Maryland |
| 20 | Mary Ridgley | 21 | Daughter | — | Maryland |
| 21 | William Ridgley | 1 | Grandson | — | Maryland |
| 22 | Thomas Berrigan | 33 | Lodger | Laundryman | Virginia |
| 23 | Celeste Berrigan | 24 | Lodger | Laundryman | Maryland |
| 24 | Isabelle Wade | 60 | Head | Cook | Maryland |
| 25 | Rebecca Bailey | 32 | Niece | — | Maryland |
| 26 | Sylvester Bailey | 21 | Nephew | Porter | Maryland |
| 27 | Benedict Wade | 30 | Nephew | Porter | Maryland |
| 28 | Joseph Wade | 50 | Nephew | — | Maryland |
| 29 | Annie Wade | 80 | Sister | — | Maryland |
| 30 | Rebecca Johnson | 50 | Head | — | Maryland |
| 31 | Matthew Johnson | 51 | Husband | Janitor | Maryland |
| 32 | Walter Johnson | 15 | Son | — | Maryland |
| 33 | Lawrence Johnson | 16 | Son | New Worker | Maryland |
| 34 | Milton Johnson | 13 | Son | — | Maryland |
| 35 | Gladys Johnson | 33 | Daughter | Domestic | Maryland |
| 36 | Josephine Johnson | 13 | Daughter | — | Maryland |
| 37 | Irvin Johnson | 26 | Son | Laborer | Maryland |
| 38 | Hattie Summs | 59 | Sister | — | Maryland |
| 39 | Arthur Sidney | 39 | Lodger | Cement Worker | Maryland |
| 40 | Zelda Sidney | 25 | Lodger | — | Maryland |
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1940 United States Federal Census (NARA). Our Model Tree links this person across census decades using XGBoost-based record linkage, with per-link confidence scores. Household corroboration strengthens the signal when co-residents appear on the same census pages in multiple years.
Source: National Archives and Records Administration (NARA)